Type-writer.



understood from that embodiment of 'ment carrier.

. UmTnn STATES PATENT carton JAMES o. WALLACE, or new YORK, NY.

'IYiPE-WRITER. 7

Specification of Letters Patent. -Pa,t nt d 0ct 20"1914 Apfplicati'onfiled June a, 1913. Seria1No.771;, 512.

To all whom it mag concern;

Be it known that a citizen of the. United, States, residing at New York' city, in the county of New and State of New York, have invented new and useful Improvements in Type-Writers,

of which thefo lowing is a specifi-cation.

The general object of the invention is to improve the construction of the escapement mechanismof typewriting machines in point of reducing to a minimum thenumber of parts heretofore employed in the construction of this mechanism, And to this end the invention resides in certain Combinations and arrangements of parts hereinafter more fully described and particularly pointed out in the appended claim.

Other objects will appear and be better my 111- vention of which the following is a specificati'on, reference being bad to the accompanying drawings forming part hereof, in w ich:-

- Figure 1 is a vertical longitudinal section I of a typewriter frame showing my invention partly in section and elevation Fig. 2 is a etail perspective of the arbor or escape- Fig. 3 is a sectional detail showing the escapeinent pawls. Fig. 4 is a fragment of one end of the carriage.

The elements of ,the escapement mechanism are herein shown to comprise a rack bar 5, a stationary pawl 7 and a movable spring actuated pawl 6. The rack bar 5 'is positioned on the bottom of the'carriage 8 so that its teethinto the space between the guides 9-9.

The pawls 6 and 7 are arranged so as to cross and intersect the ath of movement of the rack bar 5, tioned so that the movable pawl G'normally engages with the rack bar and when so en gaging it is rocked out of its normal position by virtue of the pull exerted thereon by the spring-actuated carriage 8. This has the effect of tensioning the spring 10 of the: said pawl'6 so that upon lateral movement in the direction 'shownby the dotted lines in Fig. 1, the said pawl will be re stored to its normal from engagement with the rack bar 8. Prior to final disengagement of the said pawl from the rack bar the succeeding stationary pawl 7 following the movement of the pawl 6 takes the same tooth in the rack I I bar which the I,- JAMESG., WALL.- \CE, hold the rack bar and the parts connected York wholly disengaged from the of th yoke is preferably extend downwardly and the; said pawls being posiv position when moved 7 pawl 6 is leaving, whereby,to

thereto, stationary, when the pawl 6 is upon being freed the said pawl 6 is rocked to ts normal position by the action of its spring 10 and the distance between its former and normal position corresponds to that between remote sides of adjacent teeth in the [rack bar or approximately so, where by, to have the said pawl 6 engage with the tooth succeeding that engaged by the pawl 7 while the said pawls are being restored to their normal positions, as shown in Fig. 1.

N ow inasmuch as the carriage is actuated by a spring (not shown) to move in one dierection it will be manifest that the arrangement of the pawls is such as to control the a step by step move ment each time that the pawls are oscillated into and out ofthe path of movementof the rack bar. The mechanism which operates the pawls 6 and 7 to functions as just described is in turn operated by the elements which go to make up the key board. This mechanism includes a suitable arbor or support herein shown in the form of an in verted U-shaped yoke 11. This yoke extends transversely of the space between the sides e frame of the machine, and since the formed of a single piece of sheet metal bent into the shape shown, it is manifest that it forms a simple and inexpensive substitute for its relatively complex and expensive equivalents now employed in the ordinary typewriting machine.

he arbor is mounted to oscillate in the frame a and the pivots one of which is shown in Fig. l and indicated by 12 which support the said arbor, pass through the rack bar.- Now opposite sides of the frame a and through the openings lid-13 in the vertical limbs of the arbor. The horizbntal portion of the said arbor is suitably adapted for connection to the awls 6 and 7 the said horizontal portion ing herein shown recessed and rabbeted as indicated generally by 14; in Fig. 3, to receive the frame 15 which carries the awls 6 and 7 The universal bar is indicated by 16. Single elements are employed for effecting connection between this universal bar 16 and the arbor 11, one of such elements isshown in Fig. 1 and conforms substantially to a bell crank 17 fulcrumed as indicated at 18 and having one arm fitted to the universal bar 16 and its opposite arn'i provided with a forwardly directed extension 18. Pin and slot connections 19-19 are employed for effecting connection between the said extension 18 and one of the arms of the arbor 11, whereby to compensate for the diversity between the ,arcs of movement of the yoke and the bell cranks.

The key and spacing bars one of which is shown in Fig. l and indicated by 20, are arranged between the limbs of the arbor 11 .and fulcrunied atone end on the pin :21 and have their middle portions superimposed on the universal bar 16, whereby, to effect the rocking of the bell cranks and the oscillation of the arbor and the parts carried thereby when they are separately depressed. Suitable restoring devices such as springs, may be employed for yieldingly holding the arbor in its normal position as shown in Fig. 1 and stops may be employed for limiting the movement of the said arbor.

' bar, a key pivoted to What is claimed asnew is:

In a typewriter a Irame, a carriage movably .niounted-thereonand having a rack the frame, a bell crank lever pivoted to the frame a be! carried by the lower arm of the bell crank lever and lying under the key, a single piece yoke pivoted to the frame and having pawls mounted directly thereon and carried thereby, said pawls being engageable with the rack bar, said bell crank lever having at its upper arm a forward extension, and a pin and slot connection between the said extension and the yoke, the parts being so arranged that upon depression of the key the pawls are pulled transversely across the rack bar.

ln testimony whereof I affix my signature in presence of two witnesses. f

JAMES G. WALLACE. Witnesses:

JOHN A. DOEEGAN, Geo. A. BYBNE.- 

